Prevent reparenting of foreign window embedding container

A foreign window used to embed a Qt window into it should not end up
with changes to its own parent, as its only job is to give the embedded
Qt window a parent handle.

Pick-to: 6.6
Change-Id: If1bc89658fedf449d266bc0cc750c90b6a841a68
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

1 files changed, 45 insertions, 0 deletions

diff --git a/tests/auto/gui/kernel/qwindow/tst_foreignwindow.cpp b/tests/auto/gui/kernel/qwindow/tst_foreignwindow.cpp
index a43939a21b..ac0f78be2d 100644
--- a/tests/auto/gui/kernel/qwindow/tst_foreignwindow.cpp
+++ b/tests/auto/gui/kernel/qwindow/tst_foreignwindow.cpp
@@ -25,6 +25,7 @@ private slots:
     void initialState();
 
     void embedForeignWindow();
+    void embedInForeignWindow();
 };
 
 void tst_ForeignWindow::fromWinId()
@@ -94,5 +95,49 @@ void tst_ForeignWindow::embedForeignWindow()
     QTRY_COMPARE(nativeWindow.parentWinId(), originalParentWinId);
 }
 
+void tst_ForeignWindow::embedInForeignWindow()
+{
+    // When a foreign window is used as a container to embed a Qt UI
+    // in a foreign window hierarchy, the foreign window merely acts
+    // as a parent, and should not be modified.
+
+    {
+        // At a minimum, we must be able to reparent into the window
+        NativeWindow nativeWindow;
+        QVERIFY(nativeWindow);
+
+        std::unique_ptr<QWindow> foreignWindow(QWindow::fromWinId(nativeWindow));
+
+        QWindow embeddedWindow;
+        embeddedWindow.setParent(foreignWindow.get());
+        QTRY_VERIFY(nativeWindow.isParentOf(embeddedWindow.winId()));
+    }
+
+    {
+        // The foreign window's native window should not be reparent as a
+        // result of creating the foreign window, adding and removing children,
+        // or destroying the foreign window.
+
+        NativeWindow topLevelNativeWindow;
+        NativeWindow childNativeWindow;
+        childNativeWindow.setParent(topLevelNativeWindow);
+        QVERIFY(topLevelNativeWindow.isParentOf(childNativeWindow));
+
+        std::unique_ptr<QWindow> foreignWindow(QWindow::fromWinId(childNativeWindow));
+        QVERIFY(topLevelNativeWindow.isParentOf(childNativeWindow));
+
+        QWindow embeddedWindow;
+        embeddedWindow.setParent(foreignWindow.get());
+        QTRY_VERIFY(childNativeWindow.isParentOf(embeddedWindow.winId()));
+        QVERIFY(topLevelNativeWindow.isParentOf(childNativeWindow));
+
+        embeddedWindow.setParent(nullptr);
+        QVERIFY(topLevelNativeWindow.isParentOf(childNativeWindow));
+
+        foreignWindow.reset();
+        QVERIFY(topLevelNativeWindow.isParentOf(childNativeWindow));
+    }
+}
+
 #include <tst_foreignwindow.moc>
 QTEST_MAIN(tst_ForeignWindow)